Microwave-assisted heating: innovative use in hydrolytic forced degradation of selected drugs

Stress testing has been executed to illuminate the inherent stability characteristics of drug substances and drug products. As an alternative to the conventional hydrolytic forced degradation, which is carried out at the elevated temperature for an elongated time period, microwave-assisted heating is believed to be more promising. The later technique offers many advantages over conventional heating technique like fast, efficient heat source, a more reproducible result due to the control of parameters, eco-friendly, unlike conventional heating source, it heats up only the molecules which absorb microwave energy and not the apparatus first. Present work reports microwave-assisted hydrolytic degradation studies of selected drugs, namely Lurasidone, Risperidone, Paliperidone, Alprazolam, Escitalopram, Atomoxetine, Repaglinide, Furosemide, Hydrochlorothiazide and Olmesartan. The degradation samples were analysed by using high-performance liquid chromatography techniques. The degradation products generated by conventional and microwave heating methods were compared with respect to relative retention time. Though selected drugs have different chemical structures, the unaltered degradation profile was observed when conventional heating was replaced by microwave heating. With the proposed microwave heating technique, degradation products were generated in drastically lesser time from many hours to minutes without generation of secondary degradation products.